The metaphosphate ion (PO3-) and metaphosphate esters (ROPO2) are thought to be important intermediates in phosphorylation reactions by ATP and other phosphate derivatives, but little is known about their chemistry because of their great reactivity. We have developed a method for preparing PO3- at room temperature in the gas phase, and can also prepare methyl metaphosphate. We propose to carry out a comprehensive study of the chemistry, thermochemistry and kinetics of PO3-, CH3OPO2 and RPO2 in the gas phase, using the flowing afterglow and selected ion flow tube techniques. Based on our previous experience (including studies of PH2-, P(OCH3)3 and a host of organic and inorganic ions and neutrals) we expect to be able to determine such important properties as the basicity, electron binding energy and nucleophilicity of PO3- and the relative ratios of attack of nucleophiles on P vs. C in CH3OPO2. We believe the results will be of direct application to solution studies and will provide important guidance to future biological and chemical experiments.